Gas cartridge piercer and regulating valve



Aug. 5, 1969 c. A. HOGG GAS CARTRIDGE PIERCER AND REGULATING VALVE.Filed Feb. 28, 1968 on on 3 0m mvsmon CHPIsTOPHEE A. Ho ea ATTORNEY SPatented Aug. 5, 1969 3,459,331 GAS CARTRIDGE PIERCER AND REGULATINGVALVE Christopher A. Hogg, Ilford, Essex, England, assignor to TheBritish Oxygen Company Limited, a British company Filed Feb. 28, 1968,Ser. No. 708,840 Claims priority, application Great Britain, Mar. 2,1967, 9,987/ 67 Int. Cl. B67b 7/24 U.S. Cl. 222- 11 Claims ABSTRACT OFTHE DISCLOSURE In a valve mechanism which uses as an operating mediumgas under pressure released selectively from a bulb of liquefied orcompressed gas, an excess pressure or rate of increase of pressure isprevented by a piston supporting a bulb-piercing member. When the limitconditions are reached a dilferential pressure is produced across thepiston suflicient to move it to close the aperture in the bulbirrespective of demand and until the pressure or pressure rise hasdecreased sufiiciently.

CROSS-REFERENCE TO A RELATED APPLICATION The mechanism of this inventioncan be incorporated in a dispensing device of the type described in US.Ser. No. 525,023, filed on Feb. 4, 1966, now US. Patent No. 3,420,418 byPaul -R. Rousset et a1.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to a valve mechanism for controlling the discharge ofpressurised gas from a container.

Description of the prior art A known valve mechanism of this typeincludes a valve member movable towards and away from an orifice throughwhich gas can flow from the container; biassing means for urging thevalve member towards a position in which it blocks the orifice, andactuating means adapted to overcome the effect of the biassing means forunblocking the orifice and permitting the flow of gas from thecontainer. The gas in the container being highly-compressed, it may notbe easy to position the actuating means so that the pressure in a spacesupplied with gas from the container does not rise at an excessive rateor to an excessive value. If this space is provided with a safety valve,it is possible for the safety valve to open more frequently thanintended so that gas will be vented and thus wasted.

SUMMARY OF THE INVENTION The valve mechanism includes two chambers onopposite sides of a slidable piston carrying a bulb-piercing andbulb-sealing pin. One chamber is vented to atmosphere and the other ison the upstream side of a small orifice through which all the gas flowsto the outlet. When the pressure in this chamber rises sufiicientlybecause of excess flow the piston is forced to move so that the pinre-seals the orifice it has made in the bulb seal. Thus the mechanismoperates as a type of pressure feedback system to limit pressure risesor rates of flow.

BRIEF DESCRIPTION OF THE DRAWING The present invention will now bedescribed by way of example with reference to the accompanying drawing,

which is a diagrammatic sectional elevation showing the valve mechanismof the present invention fitted to a dispensing device of which onlypart is illustrated.

The dispensing device includes a body 2 having in it a bore 4 of whichonly part of the wall is shown. Mounted in the bore for movement alongits axis is a main valve member 6 of which the lower end (not shown)operates a valve (also not shown) to control the flow of liquid from theupper end of a supply tube dipping into the can, to an outlet spout.Movement of the valve member 6 is controlled by movement of a handle(not shown). As the main valve operating mechanism does not form part ofthe subject matter of the present invention it is not described infurther detail.

The body 2 of the device is formed with a hollow boss 8 which projectsinto the interior of a recess indicated generally by reference 10 andformed principally of an outlet chamber 12, an expansion chamber 14, anda reference chamber 16. The outlet 13 of chamber 12 is adapted to beplaced in communication with the free space above the liquid in the canby means which is not shown.

The boss 8 supports a cam follower 18 which is slidable along the axisof the cylindrical passage in the boss under the control of the mainvalve '6. The cam follower 18 carries a ball 20 mounted at the outer endof a recess housing a mass 22 of resilient material biassing the ball 20outwardly of the follower 18. The ball 20 is aligned with a cam surface24 on the members 6 so that as member 6 moves up or down as viewed inthe drawing the follower 18 is able to move horizontally. The valvememher '6 is in fluid-tight engagement with the walls of the bore 4, orwith a bush 26 therein, by means of O-ring seals 28. Similarly the camfollower 18 is sealed to the walls of the passage in the boss 8 by meansof an O-ring 30.

Positioned in the recess 10 is a barrier member 32 rather similar inform to a cup seal. Member 32 acts as a barrier between outlet chamber12 and expansion chamber 14, the two chambers being in communicationwith each other through a narrow passage 34 in member 32. Member 32 isin fluid-tight engagement with the annular end face of the boss 8, bymeans of an integral circular rib 36, and is in fluid-tight engagementwith the cylindrical wall of the recess 10 by means of a flange 38shaped so that a pressure difference between the expansion chamber 14and the outlet chamber 12 is effective to force the flange 38 intofirmer engagement with the outer wall of the recess 10. Thus the onlypath for gas from the expansion chamber 14 to the outlet chamber 12 isthrough the passage 34, of which more than one may be provided in member32.

Also positioned in the recess 10 is a carrier member 40 which acts as amovable partition between expansion chamber 14 and reference chamber 16.Carrier 40 has a cylindrical head which is slidable along the outercylindrical surface of the recess 10, and is kept in fluid-tightengagement therewith by means of an O-ring seal 42. The carrier 41 alsohas a cylindrical portion of smaller diameter which is a sliding fit inthe passage in the boss 8. Although the carrier 40 is not mechanicallysecured to follower 18 it is normally held in engagement with it so thatthe two members move in unison by inwardly-directed forces which act onthe combination.

Mounted in the carrier for relative motion along the axis of the passagein the boss 8 is a plunger 44 formed at one end with a conical point 78for piercing the seal 60 of a bulb 46 containing carbon dioxide underhigh pressure.

Mounted in a peripheral groove in member 44 is a circlip 48 of resilientmaterial. The adjacent radial surface of carrier 40 is provided with anannular recess 49 so as to define a radially-spaced annular seat 50which the outer part of the circlip 48 is adapted to contact. When thecirclip is unstressed it lies in line with a surface defined by the seat50. However when a sufiicient axial force is exerted on the plunger 44it is able to move axially in the appropriate direction by compressionof mass 22 of resilient material and by flexure or dishing of thecirclip 48, the extent of which is limited by the circlip coming intocontact with the base of the recess 49. Thus the combined effect of thecompressed mass 2 and the flexed circlip 48 is to bias the plunger 44towards the bulb 46.

Screw-threaded in a continuation of the inner walls of the recess is asupport 80 comprising a cylindrical wall 52 in which is mounted anO-ring 54 adapted to make a fluid-tight seal with the neck of the bulb46. The support 80 also comprises an end wall 56 provided with a centralaperture 58 through which extends the pointed end 78 of the plunger 44.When the bulb is positioned relatively to the support 80 the seal 60 ofthe bulb is axially aligned with the passage 58 and with the end of theplunger 44 so that relative axial movement of the plunger and bulbtowards each other is effective to cause the pointed end 78 of theplunger 44 to pierce the seal 60. The metal of the seal 60 is reltaivelyductile so that an appropriate axial bias on the plunger 44 is able tokeep the pointed end of the plunger seated so firmly in the hole it hasmade through the seal 60 that the flow of carbon dioxide from the bulbis completely blocked.

Retained by a washer 62 on wall 56 is one end of a sleeve 64 ofresilient material which extends into the interior of thesubstantially-cylindrical recess 66 in the carrier 40. A helicalcompression spring 68 extends between the washer 62 and the circlip 48so as to bias the plunger 44, and with it the carrier 40, away from thesupport 80. The sleeve 64 shrouds a major portion of the axial length ofthe spring 68.

A passage 70 in the carrier 40 places the interior of the recess 66 intocommunication with the expansion chamber 14, and the pointed end 78 ofthe plunger 44 is a relatively-loose fit in the aperture 58 so that anygas which emerges through the hole in the seal 60 is able to pass intothe recess 66.

The reference chamber 16 is in communication with the atmosphere througha passage 72. Thus when gas under pressure passes into the interior ofthe recess 66, a radial differential pressure is exerted on the sleeve64 so that the lip 74 at the outer end of the sleeve is forced intofluid-tight engagement with the cylindrical wall of the recess 66 toprevent gas escaping to the atmosphere.

Connected between the interior of the outlet chamber 12 and theatmosphere is a pressure-relief valve shown diagrammatically at 76.

Under the rest conditions illustrated in the drawing the pointed end 78of the plunger 44 is in sealing engagement with the hole which it hasmade in the seal 60, being kept in engagement by the axial bias impartedby compression of the mass 22 and by fiexure of the circlip 48. Thespring 68 is effective to bias the carrier 40 and follower 18 to theleft as viewed in the drawing, so that the hall 20 is in engagement withthe valve member 6 under the force exerted on the ball 20 by theresilient mass 22. The pressures of the outlet chamber 12 and theexpansion chamber 14 are equal to each other and to the pressure of thegas above the surface of the beer or oher liquid in the can to which thedispensing device is attached, the spaces being intercommunicated bypassage 34 and outlet 13.

When it is desired to dispense beer from the can, the valve member 6 ismoved upwardly. The presence of the cam track 24 enables the camfollower 18 and carrier 40 to move to the left as the spring 68decompresses, but the effect of the resilient mass 22 and the flexedcirclip 48 is initially to keep the plunger 44 in sealing engagementwith a hole it has made in the seal 60 by permitting the carrier to moverelatively to the plunger. However after movement for a short distancethe mass 22 is decompressed and the circlip 48 is unfiexed, so that theplunger thereafter moves with the carrier and retracts its pointed end78 from the hole in the seal to permit carbon dioxide under pressure toflow through the aperture 58 into the recess 66, and from there to theexpansion chamber 14 through the passage 70. Because of the narrownessof the passage 34 the flow of carbon dioxide from the expansion chamber14 to the outlet chamber 10 is restricted so that a differentialpressure is developed across carrier 40. With the continued fiow of gasfrom the bulb 46 this pressure increases until the pressure in chamber14 at first balances and then overcomes the combined effect ofatmospheric pressure in chamber 16, the force of spring 68 and the gaspressure in the bulb 46 on the effective cross-sectional area of thepoint 78, to force carrier 40 and therefore plunger 44 to move to theright as viewed in the drawing until the point 78 of plunger 44 reducesor stops the flow of gas from the container 46. By these means theexcessive flow of gas from the bulb 46 is prevented even while the maindispensing valve is open. When the pressure in chamber 14 drops below acertain value, and the main valve is still open, the forces urging thecarrier 40 to the left overcome the bias exerted by chamber 14 and thusthe point 78 is withdrawn from the seal 60 to admit more gas into recess66 and the operating cycle is repeated. Of course, should the pressurein the outlet chamber 12, and therefore that above the liquid in thecan, rise above a pre-set value, then the pressure-relief valve 76 opensto vent gas to the atmosphere.

When it is desired to stop dispensing beer from the can the handlecontrolling the main valve member 6 is operated so that member 6 islowered and the cam track 24 indirectly forces the point 78 into sealingengagement with the seal 60, as described above.

It will thus be seen that the present invention provides a valvemechanism adapted automatically to stop or reduce the discharge of gasfrom a container of pressurized gas upon the occurrence of an excessrise of pressure in an expansion chamber forming part of the valvemechanism.

Although the illustrated valve mechanism is intended to be used with aspecifically-designed dispensing device, it is conceivable that otherforms of valve mechanisms of the present invention could be fitted toexisting dispensers.

I claim:

1. A valve mechanism for controlling the discharge of gas stored underpressure in a container, the body of the mechanism having in it a recesshousing a barrier member forming one wall of an outlet chamber, andhaving in it at least one passage connecting the outlet chamber with anexpansion chamber having one wall formed by a slidable carrier influid-tight engagement with the wall of the recess, the carriersupporting a plunger adapted to pierce a seal in a wall of a containerof pressurised gas, the carrier being movable axially, in a container ofpressurised gas, the carrier being movable axially, in response tovariations of the pressure in the expansion chamber, between a closedposition in which the plunger blocks or partially blocks the passage ithas made in the seal, and an open position in which it unblocks thepassage to enable gas to flow from the container to the interior of theexpansion chamber, and from there to the outlet chamber.

2. The mechanism claimed in claim 1, in which the side of the carrierremote from the expansion chamber is in communication with theatmosphere.

3. The mechanism claimed in claim 1, in which at least the neck of thecontainer is received in a fluid-tight manner in a support secured tothe body, the support having in it a passage through which the piercingend of the plunger passes, and in which a compression spring biasses theplunger and carrier axially away from the support to the open position.

4. The mechanism claimed in claim 3, in which the plunger carries anoutwardly-projecting member of resilient material adapted to engage aportion of the carrier spaced from the plunger to provide an axial forceresisting further relative axial movement of the plunger as theresilient member is stressed by such relative axial movement.

5. The mechanism claimed in claim 4, in which the resilient member isadapted to contact another portion of the carrier to prevent furtheraxial movement of the plunger after the plunger has moved against theaxial force through a chosen distance.

6. The mechanism claimed in claim 4, in which the resilient member is acirclip.

7. The mechanism claimed in claim 6, in which the compression spring isseated on the circlip.

8. The mechanism claimed in claim 3, in which the support carries oneend of a sleeve of resilient material which encircles at least a majorportion of the length of the compression spring, in which the sleeve ismounted within a recess in the carrier with its free end contacting orclosely adjacent to the wall of the carrier recess, and in which theoutside of the sleeve is in communication with the said remote side ofthe carrier whereby a radial differential pressure across the sleeve isefiective to force the sleeve into fluid-tight engagement with theinterior of the carrier recess.

9. The mechanism claimed in claim 1, in which the outlet chamber is incommunication with a pressure-relief valve.

10. The mechanism claimed in claim 1, in which a member movable with thecarrier carries a follower in engagement with a cam surface on atransversely-movable main valve member of which movement in theappropriate direction frees the carrier for movement from its closedposition to its open position.

11. The mechanism claimed in claim 10, in which the follower ismechanically connected to the said movable member through a mass ofresilient material.

References Cited UNITED STATES PATENTS 9/ 1925 Hawkins 2225 X 8/ 1966Butters et al 2225 U.S. Cl. X.R. 137318;22261

